Changer.



ll rrE *STATES PATENT OFFICE.

JOHN THOMSON, OF BROOKLYN, NEW YORK, ASSIGNOR TO JOHN THOMSON PRESS COMPANY, OF JERSEY CITY, A CORPORATION OF NEW JERSEY.

CHAN

NEW JERSEY, AND NEW YORK, N. Y.,

GER.

SPECIFICATION formingpart of Letters Patent No. 717,138, dated December 30, 1902.

Application filed January 7, 1902. Renewed September 29, 1902. ScrialNo.125.336. (No model.)

T all wtont it Wray concern.:

Beit known that I, JOHN THOMSON, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Changers, of which the following is a specication.

My invention relates to ink-distributing devices for printing-presses, and more particu- Io larly to the self-contained type of distributing-roller known as the duplex-screw distributer or changer, and it has for its object to secure more am ple lubrication, greater durability, and facilitate manufacture, and

this I effect by an improved construction which is less expensive than heretofore.

It is well known by those skilled in the art that in the prior construction of the duplex or cross screw changer there is excessive Wear of the parts, producing imperfect action, breakage, and increased cost of maintenance. By means of myimproved construction I overcome these objections, as described hereinafter and as shown in the accompanying drawings, in Which-,

Figure lis a longitudinal center section of the changer complete; and Fig. 2 is an end view on the line A, Fig. l. v

In said drawings, B represents the changersleeve; C, the changer-shaft; D, the duplex or cross thread screw, in which operates the pivoted crescentor switch E, whose spindle vibrates in the hollow screw F.

The general operation of the crescent in the duplex thread, vibrating at each end of the thread and causing it to traverse back and forth, thereby hauling the sleeve as it is revolved and producing the so-called changer action, is too well known to here require description.

In previous practice and also as shown in my improved construction, as in my application for Letters Patent, Serial No. 66,715, filed July l, 1901, the duplex thread has been formed directly in the changer-shaft, and Aits disposal has been such that as the changersleeve travels back and forth the threads are alternately covered by the sleeve-bearings and exposed. Bearing in mind that the changer is operated by frictional contact on the distributing-rollers covered with ink, the

consequence is that the bearing-surfaces can only be very sparingly lubricated. Moreover, when the threads become worn and inoperative the entire shaft must be discarded, and the said construction results in a rapid wear of the parts.

Now byforining the cross-thread in a part separate from the shaft, as a threaded sleeve on the shaft, with the threads cut in the outer 6o surface thereof and then iXedly applying this sleeve to the changer-shaft, as by the pin I-I, not only may va new part be readily substituted without impairing the shaft in any way, `butany material different from that in the shaft and best adapted for the duty required of the actuating part may be advantageously'ernployed at a minimum cost.

One mode of construction is shown in which the changer-sleeve is formed of two sections, 7o preferably of about equal length and suitably joined together, as by means ofthe screw connection J. This permits the sections of the changer-sleeve to be detached for ready access to the parts. Suitably disposed Within 7 5 one of the abutting ends of the sleeve are mounted the4 hollow screw F and crescent E to engage the duplex thread of the threaded part D. Preferably the chan ger-sleeve is provided with two interior diaphragms M N, 8o which may also serve as additional bearings for Vthe shaft. These diaphragms, with the sleeve B, in'close a space or chamber P, which Serves as an oil-receptacle, which may be wholly or partially filled with oil, so that upon 8 5 each and every revolution of the changersleeve the threads of the screw and all. the bearing-surfaces of all the parts will be cornpletely flooded with oil. Thus not only is the lubrication of themost perfect character, but 9o there is no dan ger of escape of oil to deterioratethe ink of the distributing-rollers. It is found that the increased durability due to this system of lubrication is at least six times that of previous designs.

Without limiting myself to the precise construction shown, I claiml. The combination of a changershaft, changer-sleeve mounted thereon and carrying a crescent, and an operating-screw, the 1o sleeve having an oillreeeptaeie,substantially In testimony whereof I have signed my as set forth. name to this specification in the presence of 1o v 2. The combination of a. Changer-shaft, two subscribing Witnesses. changer-sleeve mounted thereon and oarry- 5 ing a. crescent, and an operating-screw, the JOHN THOMSON' sleeve having partitions'on opposite sides of Witnesses: the screw forming an oil-receptacle, substan- JOHN MOKINNON, tially as set forth. HELEN M. BLANCHFIELD. 

